With boilers, the boiler main body is suspended by a steel support frame so that thermal expansion of the boiler main body during operation is not obstructed. Accordingly, when an earthquake occurs, the boiler main body exhibits pendulum motion inside the steel support frame like that of a hanging bell. As such, seismic damping devices are provided to restrict relative displacement between the boiler main body and the steel support frame.
For example, Patent Document 1 proposes a boiler seismic damping device including elastoplastic elements between a back stay provided outward of the boiler main body and a steel support frame suspension supporting the boiler main body; wherein the elastoplastic elements are divided into a plurality of groups.